http://www.msxlabs.org/forum/son-haberler/53994-m...miyor-musunuz.html
You will find a file named MsgPlusH.dll in the attachment of the first post of the thread above. You must download and replace it with the file in Messenger Plus! 3's installation folder. But make sure your Messenger is completely closed while performing pasting operation.
But at this time, the version number which reflects in your Messenger's About... window may be important. If the above soluion doesn't work, then download the second msnmsgr.zip file from the attachment of that post and replace it with the file in Messenger's installation folder. This should solve the problem.